Many types of trailer hitching devices and draw bars and the like, are known in the prior art. However, during the backing-up operation as in the case of parking the trailer in a parking area, considerable problems often arise in connection with moving the drawn vehicle in the desired direction.
An example of prior art is shown for instance in U.S. Pat. No. 3,191,967 issued June 29, 1965 to C. J. Penk and entitled "Direction Control Trailer Hitch". However, such an arrangement necessitates considerable, relatively heavy parts, and is not entirely satisfactory. Other prior art patents relating to trailer coupling devices are shown for instance in U.S. Pat. No. 2,685,454 dated Aug. 3, 1954 and U.S. Pat. No. 3,556,558 dated Jan. 19, 1971.